/* Convert 32-bit wide character to multibyte character.
Copyright (C) 2020-2021 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see . */
/* Written by Bruno Haible , 2020. */
#include
/* Specification. */
#include
#include
#include
#include "attribute.h" /* FALLTHROUGH */
#include "localcharset.h"
#include "streq.h"
size_t
c32rtomb (char *s, char32_t wc, mbstate_t *ps)
#undef c32rtomb
{
#if HAVE_WORKING_MBRTOC32
# if C32RTOMB_RETVAL_BUG
if (s == NULL)
/* We know the NUL wide character corresponds to the NUL character. */
return 1;
# endif
return c32rtomb (s, wc, ps);
#elif _GL_LARGE_CHAR32_T
if (s == NULL)
return wcrtomb (NULL, 0, ps);
else
{
/* Special-case all encodings that may produce wide character values
> WCHAR_MAX. */
const char *encoding = locale_charset ();
if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
{
/* Special-case the UTF-8 encoding. Assume that the wide-character
encoding in a UTF-8 locale is UCS-2 or, equivalently, UTF-16. */
if (wc < 0x80)
{
s[0] = (unsigned char) wc;
return 1;
}
else
{
int count;
if (wc < 0x800)
count = 2;
else if (wc < 0x10000)
{
if (wc < 0xd800 || wc >= 0xe000)
count = 3;
else
{
errno = EILSEQ;
return (size_t)(-1);
}
}
else if (wc < 0x110000)
count = 4;
else
{
errno = EILSEQ;
return (size_t)(-1);
}
switch (count) /* note: code falls through cases! */
{
case 4: s[3] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x10000;
FALLTHROUGH;
case 3: s[2] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x800;
FALLTHROUGH;
case 2: s[1] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0xc0;
/*case 1:*/ s[0] = wc;
}
return count;
}
}
else
{
if ((wchar_t) wc == wc)
return wcrtomb (s, (wchar_t) wc, ps);
else
{
errno = EILSEQ;
return (size_t)(-1);
}
}
}
#else
/* char32_t and wchar_t are equivalent. */
return wcrtomb (s, (wchar_t) wc, ps);
#endif
}